fix: native world state test issues (#8546)

This PR fixes the flaky Jest tests that were comparing the C++
WorldState against the JS implementation.

The issue stemmed from the `WorldState::get_state_reference` function
reading state reference for all five trees in parallel and saving that
information in a `std::unordered_map`. Concurrent writes to a
`std::unordered_map` [are
invalid](https://devblogs.microsoft.com/oldnewthing/20231103-00/?p=108966)
so I've added a lock to ensure that only one thread writes at a time.
Simultaneous reads are fine though.

Author: alexghr

barretenberg/cpp/src/barretenberg/world_state/world_state.cpp

@@ -9,6 +9,7 @@
 #include "barretenberg/world_state/tree_with_store.hpp"
 #include "barretenberg/world_state/types.hpp"
 #include <memory>
+#include <mutex>
 #include <stdexcept>
 #include <tuple>
 #include <unordered_map>
@@ -96,18 +97,19 @@ StateReference WorldState::get_state_reference(WorldStateRevision revision) cons
 {
     Signal signal(static_cast<uint32_t>(_trees.size()));
     StateReference state_reference;
+    // multiple threads want to write to state_reference
+    std::mutex state_ref_mutex;
+
     bool uncommitted = include_uncommitted(revision);
 
     for (const auto& [id, tree] : _trees) {
-        std::visit(
-            [&signal, &state_reference, id, uncommitted](auto&& wrapper) {
-                auto callback = [&signal, &state_reference, id](const TypedResponse<TreeMetaResponse>& meta) {
-                    state_reference.insert({ id, { meta.inner.root, meta.inner.size } });
-                    signal.signal_decrement();
-                };
-                wrapper.tree->get_meta_data(uncommitted, callback);
-            },
-            tree);
+        auto callback = [&signal, &state_reference, &state_ref_mutex, id](const TypedResponse<TreeMetaResponse>& meta) {
+            std::lock_guard<std::mutex> lock(state_ref_mutex);
+            state_reference.insert({ id, { meta.inner.root, meta.inner.size } });
+            signal.signal_decrement();
+        };
+        std::visit([&callback, uncommitted](auto&& wrapper) { wrapper.tree->get_meta_data(uncommitted, callback); },
+                   tree);
     }
 
     signal.wait_for_level(0);

yarn-project/world-state/scripts/build.sh

@@ -5,15 +5,16 @@ set -e
 cd "$(dirname "$0")/.."
 
 # relatiev path from the directory containing package.json
-WORLD_STATE_LIB_PATH=../../barretenberg/cpp/build/bin/world_state_napi.node
+WORLD_STATE_LIB_PATH=../../barretenberg/cpp/build-pic/lib/world_state_napi.node
+PRESET=${PRESET:-clang16-pic}
 
 build_addon() {
-  (cd ../../barretenberg/cpp; cmake --preset clang16-pic -DCMAKE_BUILD_TYPE=RelWithAssert; cmake --build --preset clang16-pic --target world_state_napi; echo $PWD; mkdir -p build/bin;  cp ./build-pic/lib/world_state_napi.node ./build/bin/world_state_napi.node)
+  (cd ../../barretenberg/cpp; cmake --preset $PRESET -DCMAKE_BUILD_TYPE=RelWithAssert; cmake --build --preset $PRESET --target world_state_napi; echo $PWD; mkdir -p build/bin;  cp ./build-pic/lib/world_state_napi.node ./build/bin/world_state_napi.node)
 }
 
 cp_addon_lib() {
   if [ -f $WORLD_STATE_LIB_PATH ]; then
-    echo "Copying world_state_napi.node to build directory"
+    echo "Copying $(realpath $WORLD_STATE_LIB_PATH) to build directory"
     rm -rf build
     mkdir build
     cp $WORLD_STATE_LIB_PATH build/world_state_napi.node